Free Content Types
"Free" can be a confusingly-ambiguous term. After seeing misleading and/or inaccurate information published about the various types of free content available (including photos, music, videos, text, etc.), I thought it might be helpful to provide a freely-usable image that, with Euler diagram simplicity, shows how the various kinds of free content relate to each other.
Hopefully this doesn't require further explanation, but just in case:
Royalty-Free: You might pay to acquire the content, but you won't pay royalties to use it.
Free: You won't pay to acquire the content or to use it.
Creative Commons: You won't pay to acquire the content or use it, and you have specific rights granted by whatever Creative Commons license was used.
I am releasing the image under the Creative Commons: Attribution license, which means you can use it pretty much however you want as long as you give me credit. (Read the license for specifics.) If you want to use the bitmap image, please copy it to your server instead of using my bandwidth. If you want to modify it, the source SVG file would be a good starting point. (Image created using Inkscape.)